RMC – Ready Mix Concrete
Ready Mix concrete is a type of concrete that is manufactured in a factory or in a batching plant, according to predetermined specifications and then delivered in plastic condition to the required site.
Importance of RMC
Constructions Projects has seen rapid growth and keep growing where they require cost – efficient methods of carrying out projects.
The other factor being given importance is energy efficiency and sustainability.
Ready Mix Concrete meets these factor as they are batched on systemized batching plant and sent to site and energy consumption is producing RMC is greatly reduced compared with on-site mixing concrete.
Other Advantages include:
The important factor in RMC is the batching plant producing the Ready – Mix Concrete.
To ensure quality and continuous production of RMC periodical maintenance is essential.
SPEC has experience in erection, maintenance and operation of Captive RMC batching plants that can enable to produce continuous supply of Ready- Mix Concrete.
Non – destructive testing is done to evaluate and inspect the quality of the existing concrete for irregularities differences in characteristics without causing physical damage to the concrete structure.
The two economical and reliable methods to obtain quality and compressive strength of concrete quickly are Rebound Hammer Test and Ultra Sonic Pulse Velocity Test.
This test can be used to assess the:
When the rebound hammer is pressed against the surface of the concrete, the spring controlled mass rebounds and the extent the plunger rebounds is noted from the graduate scale and is taken as the rebound number.
The Rebound hammer test helps to form an immediate correlation with obtained and the expected compressive strength of the concrete surface.
This test can be used to assess the:
In the UPV test, the pulse generated travel from the emitter to the receiver under a known distance and the time of travel is recorded. With these known data the velocity of the generated pulse can be evaluated based on which the quality of concrete can be assessed.
Based on the access to surface of the concrete, there three known methods of measuring pulse-velocity. In this direct transmission is considered a more suitable option.
Soil characteristics tend to change with time and nature resulting in changes in volume and strength of soil which eventually result in the distress of masonry and concrete structures.
The soil shrinkage and volume raise can affect the foundation which results in development of cracks on the elements of a building.
Lime treatment provides an economical way of soil stabilization.
Soil treatment with lime can help achieve significant modification in the properties of soil to improve strength and stability of the soil matrix.
Lime stabilization shall be set up through the installation of lime piles in the pre-determined location with a specific spacing.
The holes are bored to the required diameter and the perforated casing shall be inserted inside the hole. The lime slurry, a mix of lime, water and sand in a suitable ratio shall be pressure injected in the bored holes installed with perforated casing pipe.
The lime slurry injected flows through the crevices and holes in the sub-soil and reacts with the present clay.
Following reactions has major contribution to the soil modifications:
The injected lime reacts with clay and undergoes pozzolanic reaction forming cementitious compounds that imparts strength to the surrounding soil which increases the soil bearing capacity.
Lime reacts with clay particles to undergo flocculation modifying clay particles to friable characteristics, into needle like shape enabling interlock between particles which makes clay less susceptible to water content changes and drier. The increase in the plastic limit results in the soil behaving as a drier material at the same moisture content.
Lime undergoes cation exchange with soil particles which is responsible for the changes occurring in the plasticity characteristics of the soil.
Cation exchange and flocculation of the clay minerals result in physical changes to the soil including an increase in the plastic limit, and are the two mechanisms mainly responsible for lime fixation.